With Republicans focusing on the economy as their strongest message for the midterms, an issue advocacy group with close ties to House GOP leadership is launching a million-dollar digital ad campaign to tout the Republican tax law.

American Action Network’s latest digital push, shared first with Roll Call, will run in the districts of 20 Republican lawmakers who voted for the GOP tax plan in December, including members of leadership and others who are more vulnerable this year.

Rep. Fred Upton, R-Mich., left, and Rep. Diana DeGette, D-Colo., hold thank you signs made by Max Schill, who’s diagnosed with Noonan Syndrome, a rare genetic condition, after the U.S. House of Representatives voted in favor of the 21st Century Cures Act on Capitol Hill in Washington in 2015. Upton and DeGette spearheaded the act. (Al Drago/CQ Roll Call file photo)

Michigan Rep. Fred Upton announced Friday he will run for re-election instead of trying to challenge Democratic Sen. Debbie Stabenow in 2018.

“I will not be a candidate for the U.S. Senate. There was a path, but today we are choosing not to follow it,” the Republican lawmaker said in a statement. The former chairman of the Energy and Commerce Committee had been publicly weighing a Senate bid for much of this year.

When a Republican congressman in July tried to strip the 2018 defense spending bill of its requirement to plan for global warming and rising sea level threats, a group of House GOP lawmakers joined Democrats to kill the effort.

With 14 months to go before Election Day, the House battleground continues to take shape. Even though there is some uncertainty about what the political climate will look like next fall and whether normal historical midterm trends will hold under President Donald Trump, the House playing field is expanding, almost entirely in the Democrats’ direction.

As we’ve mentioned plenty of times before (and will likely repeat over and over again), history puts the Republican Party at a disadvantage: The president’s party has lost seats in 18 of the last 20 midterm elections, with an average loss of 33 seats. Democrats need to gain 24 seats next year for a majority.

As a congressman from Michigan, Vernon Ehlers used his physics background to advance environmental and STEM legislation for nearly two decades. (CQ Roll Call file photo)

The first research physicist ever elected to Congress, Vernon J. Ehlers was known for his legislative work to bolster scientific research and education, raise fuel economy standards, and protect clean air and water.

Ehlers, who represented Western Michigan in Congress for nearly two decades, died Tuesday at the age of 83. His death was confirmed by the Zaagman Memorial Chapel in Grand Rapids, which did not immediately indicate the cause of death, The Detroit News reported.

A House caucus that supports legislation to combat climate change may be joined by key Republican energy influencer who would raise its credibility among GOP lawmakers.

Rep. Fred Upton, R-Mich., the former Energy and Commerce chairman who leads the committee's energy panel, is considering joining the bipartisan 48-member Climate Solutions Caucus, a group equally divided between Democrats and Republicans.